A riot involving 2,000 people had erupted at dorms near the Foxconn factory on Sunday night

Apple supplier Foxconn reopened a manufacturing facility in China on Tuesday a day after it closed following a mass riot involving 2,000 workers that was later brought under control by local police.

Foxconn spokesman Simon Hsing said the company's manufacturing facility in the Chinese city of Taiyuan was back to normal, with its production lines in full operation.

The Taiyuan facility employs 79,000 workers, and manufactures the iPhone 5, according to labor protection group China Labor Watch.

The riot originally erupted on Sunday night from a "personal dispute" between employees, and then escalated into what Foxconn said was an "incident." Internet users immediately posted pictures and videos of the event and its aftermath, showing workers assembling in the night, along with cars turned over and store windows broken. 40 people were injured, but no one was killed.

But while Foxconn claims the dispute was not work-related, labor experts point to Chinese media reports and Internet posts that have said the riot was sparked when security guards beat Foxconn workers at an employee dorm.

Li Qiang, founder of China Labor Watch, said in an email, the dispute likely erupted into a riot because Foxconn places little value on workers' rights, along with the pressure Foxconn employees face while working on the production lines.

"Foxconn's security guards will often bully workers. If it's taken too far, this will cause workers to resist, which will then spark a riot," he said.

China's state-run Xinhua News Agency said authorities sent 5,000 police to stop the riot. On Tuesday, police were still in the area, monitoring street corners and a main entrance to Foxconn's Taiyuan manufacturing facility.